Yea it depends on who is on the server at the time. Some people just cannot be bothered. I've played frontier yesterday with a full server. Other times half the server left and the rest stayed for the rest of the map and a few more joined. Only today did it completely kill the server.
I say we leave it on a bit longer, let the regular player base to get a feel of it and dl it. If it continues to be a server killer, we'll kill it.